Timpani with quick, accurate and programmable tuning system

ABSTRACT

Timpani with quick and accurate tuning are shown. Each of timpani has a motor to drive the mechanism which gives variable tension to the head. Given tone is transformed to period of vibration and then to target displacement value of head rim against body. Motor is driven so that the head rim reaches the target displacement. Parameters of transform function to transform period to target displacement are stored, and updated, when head sounds and pair data of period of head vibration and the displacement are acquired, so that pair data fit the transform function. Combination of tones can be programmed stepwise in advance. In performance, steps are advanced by foot pedal or touch pad and tone changes of timpani are quickly done without sound. Muffling device is equipped and its action s are programmed with tone change.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on Provisional Application No. 60/727,414,filed Oct. 17, 2005.

BACKGROUND OF THE INVENTION

This invention is related to advanced timpani, or kettledrum in anotherword, which are equipped with quick and accurate tuning system. It isalso related muffling apparatus for timpani. And it is further relatedto new feature of tuning and muffling programming.

Timpano, singular form of “timpani” which is plural form, produces soundwith clear pitch. A circular membrane called head covers a bigkettle-like body. Rim of head is pressed to body by a hoop. In old time,six or eight hand screws around the hoop moved relative position of hoopto body, and then changed tension of the membrane. Player changed thepitch by adjusting the tension of membrane. It took time to adjust allsix screws precisely for head to produce sound of required pitch tone.Until around year 1800, music composer had to compose under constraintof this matter when using timpani. It was common not to change the toneof timpani within one movement.

Then, improved timpani were invented, with which player could changepitch of timpani by rotating one clank handle. In other severalinventions, pitch can be changed by angle of foot pedal. These motionlinks to up-down motion of a center shaft, and then the shaft links tosix or eight points of the hoop. So, player could change the pitch withone point operation. It shortened the time required to change the pitch.But proficient player, who could adjust pitch with only foot pedalwithout listening the sound, was rare. Until today many players haveoperated pedal and listened to the sound, then corrected the pedalangle. With one or a few cycle of correcting operation, timpani is tunedto correct pitch. Player cannot make loud sound for adjusting the pitch;he must do it with very soft sound not audible to audience. Also, ittakes 5 to 30 second depends on player's ability and surround sounds toadjust one timpano. According to these improvement, composers graduallycomposed music, in which timpani were changed tone in the course ofmusic. But it is not so quick enough that they often use three or fourtimpani. Also, composers take care to give players enough no-play timefor changing pitch of timpani.

Next improvement applied to timpani was attaching a tuning gage to eachtimpano. In one invention, up-down displacement of hoop was transformedto rotational angle of pointer. In other inventions, foot pedal angle ordisplacement of some mechanical point of link between foot pedal andhoop is transformed to rotational angle of pointer. In both mechanisms,there is a semi cylindrical bar aside of the pointer, and severalsliding markers on the bar, which have characters of tone on them.Player can adjust head tension by observing that pointer comes to markerof desired tone. Positions of markers are precisely set before playingof the day. With these tuning gage, trained players can change tonewithin say two seconds.

If head is made of natural skin, its tension changes by humidity ortemperature. So, even foot pedal or hoop displacement and pointerposition do not change, pitch may vary per hour. Plastic head does notreceive much effect from humidity. But, body of timpani or various partsof mechanisms may inflate with rise of temperature. As a result, ithappens that pitch is shifted even pointer of tuning gage stays at themarker. Actually, top class players do not count on tuning gages.Instead, they adjust with their ears.

Nowadays, electronic tuning meters are available to musicians. They showthe pitch of tone generated by every instrument including timpani.Furthermore, a few inventions (U.S. Pat. No. 4,741,242 and others) wereaccomplished for tuning meter dedicated to timpani. With these meters,not sounds of other instruments but only head vibration was picked up.They display nearest tone name and how much higher or lower thevibration is than the precise pitch. These means resolved the problem,which tuning gages had. And player without sharp ear is able to tuneprecisely. But, time necessary to adjust pitch does not decrease to lessthan five seconds, with these tuners or tuning meters. Because playerhas to produce sound by hitting the head and still need operation offeedback cycles.

With recent invention (U.S. Pat. No. 4,023,462), a motor drives thecenter shaft up and down, which pulls the head. This motor is drivenaccording to difference between reference period of specified tone andmeasured period from vibration of head. The motor is driven until saidperiod difference becomes to zero. Thus these form closed feedback loop,and automatic adjustment of pitch is realized. Time necessary to changetone may be in two second including time for pushing bottom to specifythe tone and hitting the head.

Summarizing former technology described above; the tuning gage madequick tuning possible, but had problem of accuracy because of variationper hour. Precise tuning technology still asked hitting head. Anyway, itis not possible to change tone consecutively in say 0.2 second, asplayed with string instrument or trombone.

Four timpani are common in modern orchestra. Composers had to think thisconstraint. In case they still needed more tones in short time,additional timpani had to be prepared around player. Or they had to askplural players to play on each set of timpani.

Player has to challenge muffling timpani, which is not well known.Player touches the head to cut off the tone. This action is calledmuffling. Correct muffling by hands is difficult technique itself Also,muffling is necessary to prevent sympathetic resonance of timpani, whichare not hit. Especially, if there are three or more timpani arranged, itis difficult to muffle all the timpani with two hands. In invention U.S.Pat. No. 3,951,032, padded damping plates driven by electromagneticdevice are touched heads according to foot switch operation. One footswitch can control all the timpani. But, to prevent sympatheticresonance, it is better to keep padded damping plates in touch statusfor timpani not use a little while. Until today to resolve thisdifficulty, just putting felt pads or something like on the heads ofunused timpani is commonly used practice. But, in modern or contemporaryworks, selection of timpani to play on moves frequently, and then tomove or take off the muffling felt pads are too cumbersome tasks.

BRIEF SUMMARY OF THE INVENTION

The first objective of this invention is to provide system for quick andprecise timpani tuning without head vibration and without hitting thehead.

The second objective of this invention is to provide system for timpanituning, which keeps accuracy against varying humidity and temperature aswell as elongation of the membrane.

The third objective of this invention is to provide system for timpanituning without hand operation, so that it is possible to change tone oftimpani while player plays on other timpani, or between two strikes onthe same timpani. Additional objective is to change tones of pluraltimpani at once.

The forth objective of this invention is to maintain some function ofpedal, such as glissando, or gradual shift of tone during roll, in thesame time to realize other objective.

The fifth objective of this invention is to provide system for mufflingaide. This means muffling not only after each hit, but also duringtuning change and not in use.

In accordance to this invention, to accomplish the first objective, sixmeans are added to conventional timpani. The first mean is a reversiblemotor, or actuator like it, for driving hoop up down. Motor rotation isstepped down and transformed to linear motion of center shaft connectedto hoop, or transformed to angular motion of a hinge, which links pedalmotion to the center shaft.

The second mean is a controller, which controls rotation of the motor.It controls direction, start and stop, and speed of the rotation. Incase using pulse motor, it controls number of pulse to supply.

The third mean is displacement encoder, which shows the verticaldisplacement of the hoop giving tension to the head. That may be encodeddirectly at the hoop. Or linear or angular movement of some point oflink in the driving mechanism from motor to hoop may be encoded. Furtheroption is to encode cumulative rotation of the motor, or it may justcounting pulses supplied to the motor in case it is a pulse motor. Nomatter which part is chosen to encode, directly or indirectlydisplacement of hoop is mapped onto some scale, and its value isautonomously updated and readable by the controller. With abovedescribed first, second and third means, displacement of any valuewithin the possible range can be reached quick and precisely. It iscommon technique for positioning control.

The forth mean is curve memory for storing data representing the curve,and readable by the controller. Here “curve” means figure of graph ofthe displacement against period or frequency of head vibration. Andexamples of “data” are a set of point data on the curve, and parametersof mathematical function approximating the graph. These data are tunedpreliminary to fit each actual combination of the head and the timpano.

The fifth mean is a console panel to receive the command and displaystatus of each timpano.

When the console receive command to change tune to some tone, controllerperforms first transformation by calculating period or frequency ofsound from the specified tone, and then performs second transformationusing data stored in the curve memory, to get target displacement fromthe period or frequency. Then, drives the motor until encodeddisplacement reaches the target displacement.

Now, in case driving direction is loosening head, controller sets subtarget to once pass the target displacement, and then switches thedirection to approach the target. This is because friction between headand body retards head to shrink enough.

Thus, without hitting the head, fast as less than half second andprecise adjustment of pitch is performed.

In accordance to this invention, to accomplish the second objective, thesixth mean, a period measuring device for head vibration, is added. Thisdevice may include microphone or set of optical emitter and detector setinside the kettle-like body. Picked up signals go through band passfilter, which passes signal component of frequency range the timpano canproduce. Period of the wave signal can be measured by counting clocksignal between two zero crossing of the signal. Measured data is takeninto the controller. Also seventh mean, vibration detector, is added.This can be a threshold circuit comparing amplitude of picked up signaland pre-tuned fixed level.

When the special initializing process for this invention is orderedbefore concert or rehearsal, controller drives hoop to three positions,low, middle and high, prompts operator and waits operator's hit of headat each stop position. So, the controller gets three pairs of data,which are head vibration period and the displacement. Then, thecontroller calculates renewal parameters for the second transformationso that three pairs of data are on the curve of the transform function.

Thereafter, every sound played is detected by vibration detector, andpair data, taken from period measuring device and displacement encoderat that moment, are stored. Then, the controller checks if measuredperiod is correct. If it is out of allowance, the controller calculatesrenewal parameters for the transform function, calculate targetdisplacement with updated transform function, and drive the motor toreach the target. Player can make soft hit on the head before play afterlong rest for check purpose.

So, playing music itself maintains the accuracy of transform functionand then tuning. So, affection from climate is compensated automaticallyand autonomously.

In accordance to this invention, to accomplish the third objective, theeighth mean of programming is added, which memorizes and reads outchanges of tones in the sequence it happens in playing music. Beforeplaying, changes of tone are input through console, step by step. Theyare stored in a tuning program memory of controller. Then, during theplaying, player give the timing of change by foot switch, and thecontroller starts driving motors on the moment. All of two to fivetimpani arranged around a player are controlled all together in the sametime.

Change in at least one timpano at some timing is memorized. Also changesof plural timpani in one timing also memorized as a group. Changes ofgroup timpani start all together with one operation. Now, not only afoot switch, one or plural buttons or pads tapped by a finger or amallet can be prepared to input timing. Also, especially for rehearsal,operation for skip or back in stepwise or fast mode to arbitraryposition in the tuning program memory is also possible at the console.On the music sheet, print or display, this position information, that isstep number and tone combination are written. Player can check ifcurrent program step or tones are correct or not, by compare writtennumber on music and number in the console display.

With this mean, even player's two hands hold mallets and busy forplaying, tone changes in a moment are possible. As consecutive changesof tone in say 0.2 second is possible with timpani of this invention,fewer timpani than ever can be enough for music works of pastrepertoire. On the other hand, composers can use timpani with far freefrequent change tone than conventional ones. It is possible to playmelody almost like trombone.

In accordance to this invention, to accomplish the forth objective, theninth means is added to detect pushing force at toe and heel parts ofpedal. The motor may be driven with speed according to the forcedetected there. Player feels this operation same as conventional pedal.And artistic expression about detail of glissando, such as timing andspeed, is kept possible even it is motor driven.

In accordance to this invention, to accomplish the fifth objective, thetenth means of muffling apparatus consisting of soft pads, actuators todepress or release the soft pads to the head from inside the timpano,foot pedal input to actuate them. The eighth mean of programming can beexpanded to specify if these soft pads staying depressed status or not.

Even hands are busy to play notes, complete muffling is possible withfoot operation. Further there is no miss about inhibition of sympatheticresonance with programmed muffling.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway view of timpano of the invention;

FIG. 2 is schematic diagram of four timpani set, showing electroniccomponents and wiring between them;

FIG. 3 is schematic diagram of a controller;

FIG. 4 is an example of console panel;

FIG. 5 is an example graph showing the relation between vibration periodand hoop displacement;

FIG. 6 is an example of pedal with censors;

FIG. 7 is arrangement of censors;

FIG. 8 is an example of bilateral control mechanism.

FIG. 9 is an example of a muffling apparatus;

FIG. 10 is a shifting unit in muffling apparatus;

FIG. 11 is a solenoid in muffling apparatus;

FIG. 12 shows touch status of muffling apparatus;

FIG. 13 shows press status of muffling apparatus;

FIG. 14 is an example of console panel with muffling control;

FIG. 15 is an example of music phrase with marks relating thisinvention;

FIG. 16 is an example of a package of data in media for timpani to playa music work.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

There are many variations to realize the invention. But, now referringto FIG. 1 to 5, one preferred embodiment of basic function is described.FIG. 1 shows cutaway view of timpano. It illustrates mechanism to changetension of head. Basic construction of timpani includes a body 1, six oreight legs 2 and a base piece 3 supporting the whole instrument, and ahead 4 put on the body 1. A head is flexible membrane laps circularmetal ring or rim 4 a. Portion of head 4, which is inside of body 1,vibrates and makes sound triggered by hit with mallet. There is sharpmajor frequency in the sound spectrum it makes, so timpani are said tohave definite pitch. The pitch is determined by diameter of body, massdensity of head membrane, and tension applied to head. To tune the pitchto specific musical tone, modern timpani have mechanism to change thetension of head in reasonably short time.

Hoop 5 has L shape section and push down the ring 4 a. Six or eight lugs5 a corresponding to legs 2 are attached to hoop 5, and bolts 6 connecteach lug and mid point 7 b of hinge 7. One end of the hinge 7 a is fixedto leg 2. The other end of hinge 7 c is connected to another hinge 9 byrod 8. Hinge 9 is connected to a center hinge 11 by another rod 10. Rods10 and a hinge 11 form an umbrella like shape. Hinge 11 is fixed tocenter shaft 12. With these links, up down movement of center shaft 12is reduced and transformed to up down movement of hoop 5 and head ring 4a. Tension of head 4 or its restoring force pulls up center shaft 12. Onthe other hand, hinge 13, supporting point 14, and counter balancespring 15 give pull down force to center shaft 12. The spring force canbe adjusted by screw 16, which moves the upper end of spring 15. Saidtwo forces, which pull up and down the center shaft, are nearlybalanced. Mechanism described in this paragraph is typical inconventional timpani.

There are variations in mechanism. In some type, umbrella like rods 10and hinge 12 are inside the body 1. Also there is some type, they are inthe base 3. Still in other type, molded metal piece called crown isattached to the center shaft and pulls down hoop 5 through several rods.Common through these types is that there is a center shaft and up downof it causes hoop displacement.

In conventional timpani, center shaft 12 is connected to foot pedal withfurther hinge mechanism, or some cam mechanism. Player adjusts headtension by angle of foot pedal. Some type of conventional timpani hasnot counter balance spring 15, but have hinge lock mechanism operable byfoot action with those types, which have counter balance spring 15, hoopkeeps displacement by friction between body edge and head.

In this embodiment, an electric reversible motor 17 drives center shaft12. Gears 18 and 19 reduce rotation of the motor. As lower part ofcenter shaft 12 has screw thread cutting, rotation of gear 19 istransformed to up down motion of center shaft 12. Bearing 20 supportgear 19 to base piece 3. There are three optical sensors, which detectcoverage by hinge 13 in each optical axis. Sensor 21 detects the lowesttension of head 4 in usual use. Sensor 22 detects further lower or notension of head 4, which is for head exchange purpose. Sensor 23 detectsthe highest limit of tension for protect head from break.

Displacement encoder 24 is installed outside the body, and a probe 25 ispushed up from inside of encoder. The probe always touches to bottom ofhoop 5. Thus, displacement of head ring 4 a, directly related to headtension, is measured. Resolution of 1 micrometer to 10 micrometer issuitable for the encoder 24. A microphone is set inside the bodysupported by bar 27. It picks up sound of head vibrations.

FIG. 2 shows horizontal view of American style four timpani arrangementand also shows position of electric and electronic components relatingto the control of pitches. In Europe, arrangement is reverse way, but itdoes not affect realization of this invention. Each component alreadyshown in FIG. 1 is shown with branch number. 3-1, 3-2, 3-3, and 34 arebase pieces usually in same size. 4-1, 4-2, 4-3 and 4-4 are heads, whichdiameters are 32″, 29″, 26″, and 23″. 17-1, 17-2, 17-3, and 17-4 aremotors. 21-1, 21-2, 21-3 and 21-4 are sensors for lowest tension point.Sensors 22 for release points and 23 for highest tension limit areomitted from FIG. 2, but they are at the same position with sensor 21.24-1, 24-2, 24-3 and 24-4 are displacement encoders. 26-1, 26-2, 26-3and 26-4 are microphones.

Now, there are system components not written in FIG. 1. Wires from or toabove components are once connected to connectors 28-1, 28-2, 28-3 and28-4. There is a controller 30 contains microcomputers and plug-ins 31-1, 31-2, 31-3 and 31-4, which are corresponding to each timpano. Ifonly two timpani are at some site, only two plug-ins are enough forsystem. Corresponding plug-in 31 and connector 28 are connected with onebound wire. There is a foot pedal 29-1, which generates just on-offsignal, connected to one of the timpani. There may be small electronictouch sensitive pads 29-2, 29-3 and 29-4. Number of electronic pads maybe chosen as zero to the same number of timpani. Pads are clipped tohoop at any position. But it is better to position along the path ofmallet movement. They can be hit by mallet or finger, and tell thesystem timing of tone change. One console panel 32 is essential to thesystem. It is put on in front of one center side timpano.

FIG. 3 is a schematic diagram of controller 30. It is like a desktoppersonal computer composition. Plug-in 31 are connected to system bus33. There are a microprocessor 34, a hard disk 35, a power unit 36, aswell as a display control unit 37, a touch panel input adapter 38, andpower switch interface 39. There is a clock pulse generator of 1 MHz 40,and deliver the clock to every plug-ins 31.

Each plug-in has four sections. Only one plug-in is detailed in FIG. 3,but others have same composition with 31 - 1. First, motor drive sectionhas motor speed register 41 - 1. The sign bit specify the direction ofrotation, and other bits specify the target speed of motor 17-1. Speedvalue is digital to analog converted, and power amplified in 41-2circuit.

Second section is for detection of vibration period. Signal frommicrophone 17-1 is received by circuit 43-1 for band pass filtering anddetection of zero crossing. With band pass filtering, only base tone ofthe timpani, which has frequency range of 70 Hz to 260 Hz, gets through.Also, 43-1 has detector of amplitude. Only when amplitude is larger thancertain threshold, a flag is set to on, and the zero crossing signals gothrough. Two zero crossing signals per one cycle go to period counter44-1, transfer the count value to output register, and reset thecounter. Counter always counts 1 MHz clock 40. On flag signal and Zerocrossing signal also initiate interrupt procedure, and micro processor34 takes in value of the output register and reset the interrupt.

Two channel signals come in from displacement sensor 24-1 to the thirdsection. Signals are read from two 0/1 patterns on a rotary disk drivenby up down motion of the prove, which are sifted a quarter cycle. Every0-to-1 and 1-to-0 edge timing is fed to counter 46-1 as up or down countpulse depending on the other channel signal. This is known method forencoding of two-way movement. Counter 46-1 always shows current hoopdisplacement, and can be read from microprocessor 34.

In the forth section, status register 47-1 reflects value of sensor21-1, 21-2, 21-3, and foot pedal or electronic pad 29-1. Signal changesin these sensors cause interrupt. Status includes setting ofdigi-switches set according to diameter of timpani.

Other than plug ins, display control unit 37 is for liquid crystaldisplay panel on the console panel 32. Touch panel input adapter 38 isalso for the console panel 32. These are general one and not describedhere. Also, LAN adapter 49 is general one.

FIG. 4 shows an example of console panel 32. It is a box with a liquidcrystal display 51 covered with a transparent touch panel. Power switch52 for system is on the side of box. Sample of display image contents atsome moment is shown here. Four timpani are shown with circles 53-1,53-2, 53-3 and 53-4. Now, 53-2 is displayed with bold line showingselected for operation. Tones set to each timpani are shown withalphabet character inside of each circle, some followed by flat or sharpsymbol. Alphabet characters 54 and flat and sharp symbols 55 and 56 aredisplayed above the four circles. Character set depends on selectedtimpano and telling available tones on selected timpano. To change tone,first select timpano by touch the circle 53, if other one has beenselected. Next, touch flat or sharp symbol 55 or 56, if necessary. Then,touch one of character 54. Controller immediately starts driving themotor. With this operation one by one instruction can be given ondemand, and it works if there is enough time for player to change tones.

For case there is no time to operate on console panel, or very busyfrequent changes are necessary, programming function is usable. Thereare three modes in the console operation of timpani of this invention,which are Play, Edit, and File. Touching respective pseudo button 57, 58and 59 in the display change mode to corresponding mode.

Now, edit mode operation is described. Play mode and edit mode use samedisplay as shown in FIG. 4. In edit mode, motors are not actuated.Setting for tones of four timpani are grouped and memorized in a programstep, which has a sequence number named program step number. Withpushing initialize button 60, all tuning program memory contents arecleared and program step number becomes 1. Program step number is shownon the display at 61. At step 1, tones of all timpani must be specified.Specifying operation is same as in play mode, that is, selection oftimpano, specifying flat or sharp if needed, and selection of tone, inthis sequence. Character display changes for the timpano by thisoperation. Pushing forward button 62 demands group setting is confirmedand stored into tuning program memory and program step goes up by one.At next step specification is necessary for only timpani need changetones. For convenience, there are backward button 63, rewind button 64,and go-to-end button 65, to navigate through steps.

File mode is used to store or load tuning program or memorized steps toor from secondary memory. Display contents are different from FIG. 4 andare some appropriate for navigation through file systems to locate thefile place, as seen in many application software. Player can useportable memory to save and reuse program step memories. It may bedownloaded through wired or wireless LAN.

Now, play mode operation is described. Hereunder controller means themicroprocessor 34 and its programs. In play mode, selected timpano istuned to specified tone right after touching any of character 54. Also,touching forward button 62 or more likely stepping on foot button 29-1,or hitting any of electronic pads 29, causes advance of program step. Assoon as program step advances, motion start at the timpani, which arespecified to change tones.

Touching initialize button 60 in play mode activates initial dataacquisition procedure for all the timpani one by one. This is a kind ofritual for player to start use of timpani. Using sensor 21, controllerdrives the motor to move the hinge 13 to the sensor position, meansposition where sensor signal changes, and head tension is at the lowest.Controller pulls down center shaft certain distance. Then make timpanocircle 53 on the display blinking and wait player to hit the head. Whenmicrophone picks up head sound and amplitude detector set flag on.Microprocessor gets a few pair data from period counter 44, anddisplacement encoder 46, stores the data and stops blinking on display.Then it drives motor to pull down center shaft certain distance andagain make circle display blinking again to ask player to hit the head.Repeat this procedure a few preset times to get pair data of periodcounter 44 and displacement encoder 46. It is not necessary that pitchbe in tune. After controller finishes the procedure on a timpano, itgoes to next timpano.

FIG. 5 shows an example of curves of displacement of hoop against periodof vibration. Thinner line curve shows an example of real data gottenfrom a timpano, and thicker line curve shows calculated according totransform function adjusted to fit the real data. In this example,second order polynomial is used as transform function. For thistransform function three pairs of data can determine three parameters,two coefficients and constant term. It seems the transform function iswell fit the real data. So, initial data acquisition described above isdone with three data for each timpano. For example in FIG. 5, if sensorpoint is at 1.0 mm, displacement at 0.9 mm, 0.6 mm and 0.3 mm are usedfor initial data acquisition. Their pitches are not necessary to be sometone in the music scale.

Interpolation or extrapolation is one of other calculation method. Moresophisticated transform function may be used for more precise fit in allthe range, but need more pairs of data to determine the parameter in thetransform function.

Frequency of each tone can be calculated using logarithm function,supposed equally tempered scale is used, and frequency of A4 is given as440 Hz or other value. Then period of sound wave is calculated asinverse of frequency. Controller keeps these periods value multiplied byone million as target value, as this system uses 1 MHz clock. Actually,to avoid heavy calculation of logarithm, all possible values of periodcan be calculated off-line, and memorized in a table format.

To tune a timpano to certain tone, controller at first gets the periodvalue corresponding to the tone from said table, and at secondcalculates target displacement by substitution of period value to thetransform function. Then drives the motor 17 until actual displacementreaches said target displacement In case going up, in other wordloosening head, controller once drive the motor so that hoop goescertain amount higher than target, then pull down it to the targetdisplacement. When it approaches to target, controller sets motor speeddepending on the distance between current and target displacement forfast and accurate positioning. There may be maximum and minimum speed todrive the motor. Also, there are many studies on optimal control foreach type of motor used to do this movement fast and accurately.

In play mode, every hit at head makes vibration of head, and it ispicked up by microphone 26, then amplitude detector set flag on andperiod counter 44 gets count value. Microprocessor takes in the countvalue, accumulates several data to calculate mean value, and compares itwith correct period of specified tone. If the difference is bigger thanpredetermined allowance, correction procedure is activated.Microprocessor reads displacement counter 46, makes pair with perioddata and stores them. Microprocessor picks up latest three such pairdata and calculates parameters for revised transform function in sameway as initialize procedure. Then it calculates the new targetdisplacement value with updated function from period of specified tone,drives the motor until hoop reaches newly calculated displacement. So,correction is autonomous, even climate change affects tension of head.

Player can plan use of timpani and tone changes for each music workpreliminary. Player can assign step number to changing point and writeit at the point on the music sheets with special mark for program stepadvance. This special mark is put on the music staff in the same waywith note, so that player can precisely set the timing of tone changesamong condense notes. It is like pedal mark in piano music. Playerinputs the tones of each timpano for steps in edit mode. Then, duringplaying music, when timing comes to written changing point with mark,player just operates on any of foot switch or electronic pads 29. Itchanges all or some timpani in a moment.

Player can save the memorized steps information into some removable diskfor next time to play the work. Publisher may provide music sheet withprogram step information, which are marks and tone combinations, writtenon it. Further more they may provide digital disk contains the stepinformation to be loaded onto timpani of this invention. There may beseveral versions corresponding to timpani set, number and sizes. Playercan load one of those files into controller in file mode and use it inplay mode looking provided music sheets. Player can modify program stepinformation in edit mode.

Now supporting feature for pedal operation referring to FIG. 6, 7, and 8is described. There are two types of embodiments that areone-directional and bilateral. FIG. 6 shows a pedal for an example ofone directional type control. A jut 71 is a part of base piece 3. A leg72 is one of bearing points of whole instrument. Therefore, back pedalplate 73 is unmoving. But, pedal plate 74 is able to tilt to anydirection. There is one rigid pin 75 at the center, which supports pedalplate 74. FIG. 7 shows sensor arrangement in the pedal plate 74. Toepush sensor unit 76 and heel sensor unit 77 have springs in them andpush back pedal plate 74. Both sensor units have some allowance andproduce signals according to pushing pressure when pushed over theallowance. Hold switch unit 78 and release switch unit 79 are momentumswitches, which have nodding action for operator's awareness of itsaction. Both switch units have springs pushing back pedal plate 74. Whenfoot is not on the pedal, the pedal plate 74 is parallel to back pedalplate 73.

With these input devices, player can accomplish pedal operation likeconventional timpani. When toe push sensor 76 detects pressure, itssignal is sent to one of plug-in 31 in controller 30. Microprocessor 34takes in the signal and drives the motor 17 with speed according tosensed pressure on toe push sensor 76 to direction pulling down thecenter shaft 12. Thus player can make quick glissando by pushingstrongly with toe, as well as gradual pitch uplift by pushing softly.When heel push sensor 77 detects pressure, motor 17 is driven todirection pushing up the center shaft 12. It makes quick or slow pitchdown.

If hold switch 78 stays off and head vibration is diminished andamplitude encoder is set off, microprocessor 34 drive the motor 17 sothat head goes back to original displacement. When hold switch 78 isturned on, microprocessor 34 stops driving motor 17 and hold theposition. This hold continues until release switch 79 is turned on, orone of foot button or electronic pads 29 is hit for changing tones.

FIG. 8 shows bilateral type of embodiment of pedal control. Back pedalplate 81 tilts around a pin 81 a Pedal plate 74, rigid pin 75, toe pushsensor unit 76, heel push sensor unit 77, hold switch unit 78, releaseswitch unit 79 are the same components with those in the previousdescribed embodiment. And, control driven by these sensors and switchesalso the same with the previously described embodiment. The differencewith the previous described embodiment is that motor 17, gears 18 and19, transform their rotation to gear portion 83 a of hinge 83, and thathinge is linked to the center shaft 12 by link 84. Also, hinge rotationis transformed to the tilt movement of back pedal plate 81 and pedalplate 74, by links 85, 86 and hinge 87. Thus, feeling of pedal operationis like conventional timpani. But player can operate with less power.There is counter balance tension spring 88 and adjusting screw 89.

In case there is no power supply and motor 17 does not work, pedal plate74 can be used to drive the center shaft 12 as in conventional timpani.There may be crutch between motor 17 and gear 83 a to reduce the backload of pedal operation during power off.

Muffling aide is described here using FIG. 9 to FIG. 14. With thisembodiment, muffling felt pad 91 is installed inside timpano body 1. Asshown in FIG. 10, felt pad 91 is pasted on the plastic plate and rod 92.Plate and rod are made of material, which is not magnetized. Bottom ofrod 92 is attached to magnet rod 93. Magnet rod 93 is permanentlymagnetized as one end 93 a is N pole and another end 93 b is S pole. Amagnetic coil 96 is hold inside housing 94, which is positioned by anarm 95 attached to the body 1. As seen in FIG. 11, four lead wires 97-1,97-2, 97-3, and 97-4 are connected to the coil 96. Electric current isgiven two ways. One is between 97-2 and 974, and the other is between97-1 and 97-3. Each generates magnetic field at lower and higherposition. In both case, top side of coil becomes S pole and pull the Npole 93 a of the magnetic rod. Also, bottom side of coil becomes N poleand pull the S pole 93 b of the magnetic rod. Then, the parts 91, 92,and 93 are raised against gravity.

When no electric current is given, felt pad 91 and plate 92 stay lowposition as shown in FIG. 9. Because felt 91 stays back from head 1,head vibration is not disturbed. We call this “open” status. Whenelectric current is applied between 97-2 and 97-4, magnet rod 93 ispulled up to generated magnetic field. Then felt pad 91 touches to thehead 1 as shown in FIG. 12. Because felt is soft, head vibration ispossible but decays fast. This is used when performing hall has too muchreverberation to reduce loudness and dump the sound faster. We call this“touch” status. When electric current is applied between 97-1 and 97-3,magnet rod 93 is pulled up to generated magnetic field, which is higherthan former case. Felt pad 91 is pressed to the head as shown in FIG.13. Then head vibration stops, no resonance occurs to the head. We callthis “press” status.

Above described embodiment using magnetic field is one sample to realizethe movement between three positions. Touch status is option. Equipmentof two status, open and press, only is useful also, and easy to realize.On the contrary, there may be interpolated position between touch andpress position, to produce different mute effects. Pedal, which hasplural resolution, is used for this purpose. Furthermore, number of feltpads in touch or press status in every timpano may be changed.

Now, three categories of events activate the hardware described above.One is direct link to a muffling foot pedal. This pedal is other thanpedal 29-1. During player push down the muffling pedal, felt pads of alltimpani move to press status or intermediate status between touch andpress, until player release the pedal. Second category of event ischanging tone. While motor is driven to change the tone, felt pads ofthe timpano are moved to press status. This prevents unnecessaryglissando sound.

Third category of event is programmed static muffling. For this purpose,display on the console panel 32 is modified as in FIG. 14. Modifiedpoints are addition of three letters at 98 and change in display of tonename of each timpani. In three letters at 98, “X” means press status,“x” means touch status, and “O” means open status. Player specifiestouch or press status to the selected timpano by pressing “x” or “X”character 98 while editing each memory step. Default is open status.Timpani not selected keep same status. Tone display of timpano specifiedas touch status changes to having “x” mark as shown at 53-1. Also, forpress status, display changes to have over written X as shown at 534. Inplay mode, as soon as step advances, electric current is applied to coil96 of timpani specified as press or touch. In play mode, manualoperation is also available to selected timpano by pressing any ofcharacters at 98. These three modes work as OR. In other word, whichgives greater pressure overrides others at each timpano.

In FIG. 14, pitch calibrating interface is shown. Number shown at window99 represents current frequency of tone of A, to which every instrumentto be tuned. And pseudo button 100 a and 100 b are used to decrement orincrement the number. Each orchestra sets this frequency before playing.We call this frequency setting as calibration. With this embodiment, allpossible periods of head vibration are memorized assuming frequency of Ais 440 Hz. To compensate according to actual calibrated frequency,calibrated periods are calculated as original period multiplied by 440and divided by calibrated frequency of tone A. This calculation isperformed when there is change in calibration frequency. Thesecalibrated frequency are used for the first transformation.

Player can set the calibration number at first. When tune of wholeorchestra is detected as shifted later, player can adjust this numbershown at the window 99 to make timpani tones match the orchestra pitch.

FIG. 15 shows an example of a piece of music, which can be played by twotimpani of this invention. Also, it shows how music sheet looks likewith special marks related this invention. There are six different tonesin this short phrase. So, with conventional timpani, and by not expertplayer, six timpani have to arrange around player without tuningchanges. Expert player able to change tone of a timpano very quickduring playing other timpano, may be able to play this phrase with fourtimpani, but it is challenging and critical. But, with two timpani ofthis invention, using programming function, it is rather easy for mosttimpani players.

In FIG. 15, notes and rest are written in staff notation 101, and fiveprogram step advance marks 102 are attached to them, with program stepnumbers 103 under the marks. Horizontal position of each mark is same asnotes or rest in this example. This means that player steps on the footpedal 29-1 in the same timing of hitting the head by hand. Alphabetcharacters 104 shows tones of two timpani after change in the programstep completes.

Now parts of controller operation performed along with this example isdescribed. When the controller receives the first signal from the footpedal 29-1 at the mark of program step number 11, it drives felt pad 91to press position to muffle the smaller timpano, which is sounding in D,and change tone from D to E. The bigger timpano stays in tone A and ishit and produce sound in A, at the same time. When change of tonecompletes, controller releases the felt pad 91 to original position, andwaits next hit. Next steps are performed in same way. One more differentkind mark 105 shows muffle timing. Player steps on two pedals; one formuffling and the other for program step advance in this example.

If there are four timpani of this invention, changes of program step canbe reduced to two for this example piece. But, playing with two timpaniis as easy as with four timpani.

Thus, with this invention, many music works can be played with lessnumber of timpani. And this is advantage at narrow stage or orchestrapit, and is convenient for transportation. Also, this invention givesmusic composers wide freedom to use timpani, gives almost conceptualchange to timpani.

FIG. 16 shows example of structure and data for information on computerreadable media, prepared for playing a music work with timpani of thisinvention. A package for one music work is shown as 110. It containsfour kind of information; music work information 111, timpani setinformation 112, tuning program information 113-116, music noteinformation 117-118.

Music work information contains identifying and describing informationabout the work, such as name of composer or arranger, type of music,serial number in the type, key or tonality, opus number and so on.

Timpani set information 112 contains many possible various setcombinations of timpani about diameter, equipped or not with programtuning function and programmable muffling function. Also eachcombination has linkage to a tuning program usable with the timpani set.Number 112 a shows how many set combinations are listed. Data in aparentice 112-1 includes information of one set combination, which arelinkage to tuning program data 112-1 a, number of timpani 112-1 b, andproperty of each timpano, that are, diameter and equipped functions. Inthis figure, diameters are shown in inch. Letter F means full equipped,T means equipped with tuning program function but not muffling function,M means equipped with muffling function but not tuning program function,N means conventional timpani not equipped. 112-2˜112-4 are informationof other set combination. Further combinations are not shown.

Tuning program information consists of heading part 113 and program part114. Heading part includes identification code, link to correspondingmusic note, number of timpani, and total step number. Program partincludes description of each step consisting step number and tone andmuffling setting for each timpano. In the figure Letter O means Open andX means Press status. Another information of tuning program is shown at115 and 116, which is for case using four timpani set. Tone setting in116-1, 116-2 and 116-3 are same but muffling setting are different.Further other information of tuning program are not shown.

Music notes corresponding each tuning program are included in thepackage. Special marks for tuning program step advance and muffling ofthis invention are filled into conventional music note. Player can useprint out or view on display such as tablet computer.

Controller of timpani may show set combinations in the media on consolepanel, and player may choose one from the list. Or controller may readin the timpani set information and find out from the data a set matchingwith actual installed timpani set. And in both case the controller loadslinked tuning program into tuning program memory.

In the figure, only one package 110 is shown, but one media may containplural packages for different music works.

1. Timpano, which has: A reversible motor linked to and drivesmechanism, which gives variable tension to the head, A controller, whichcontrol rotation of said motor, One of mechanical parts of said drivemechanism, whose value of displacement is autonomously updated andreadable by the controller, Curve memory for storing data representingthe curve, where curve means figure of graph of said displacementagainst period or frequency of head vibration, and data are such as, butnot limited to, a set of point data on the curve or parameters ofmathematical function approximates the graph, and Interface to specifytone to be tuned to, Wherein said controller performs, when requested totune to a tone, first transformation of said tone into a numberrepresenting frequency or period of head vibration, and secondtransformation of said number into target value of said displacement,then drives said motor until the value of said displacement reaches saidtarget value,
 2. The timpano of claim 1, wherein said part is a hoop,which covers and pushes the rim of head, and said displacement meansvertical position of the hoop against the body of timpano encoded bylinear displacement encoder.
 3. The timpano of claim 1, wherein saidpart is said motor, and said displacement means cumulative rotationalangle of the motor.
 4. The timpano of claim 1, which further has: Periodmeasuring device to measure period or frequency of head vibration,Vibration detector to detect that head is hit and is producing sound,Wherein said controller performs, when said vibration detector detectssound; Checks if said measured period is in allowance range or not, Ifit is not, updates said data in the curve memory using new pair of valueof said displacement and said period measuring device, so that bestfitness to said new and recent pairs of data is achieved at the secondtransformation using said updated data, and then drives said motor untilsaid displacement reaches the new target displacement, which iscalculated from correct period or frequency with second transformationusing said updated data.
 5. The timpano of claim 1, which further has:Period measuring device to measure period or frequency of headvibration, And said controller initializes data in the curve memory,wherein said initialization is conducted in such way that it drives themotor toward plural displacement in available range, lets player hitsthe head at each displacement, takes in pair data of the displacementand value of period measuring device, and then find data to be stored inthe curve memory so that best fitness to said taken in pairs data isachieved at the second transformation.
 6. The timpano of claim 1,wherein the way of driving motor, in case direction of the drive is toloosen the tension of the head, is such that once it passes the targetand then drives back to the target.
 7. Timpano or timpani of claim 1,further has: Tuning program memory for storing at least one combinationof tones to be set for each timpano, in the sequence of necessity alongperformance, Wherein said controller advances the program step when userindicates timing, and reads out the combination data of said tuningprogram memory and executes tuning of necessary timpani according to thecombination data.
 8. The timpani of claim 7, wherein a foot pedal isused for timing indication.
 9. The timpani of claim 7, wherein one orplural touch sensitive pads are used for timing indication.
 10. Thetimpani of claim 7, wherein portable memory media or outside computer isused to take out or take in contents of tuning program memory.
 11. Thetimpano of claim 1, which further has: Two glissando buttons to inputthe player's direct indication for raising or lowering the head tensionand to drive the motor as indicated.
 12. The timpani of claim 11,wherein the glissando button senses multi level to control motor speed.13. The timpani of claim 11, each timpano of which further has: Holdbutton to stop the motor and hold the head displacement, and resumebutton to drive the motor toward the original displacement.
 14. Timpano,which has: One or plural soft pads with each actuators to bring saidsoft pads to the head or remove said soft pads from the head, whereinsaid actuators take one of control positions, which are removedposition, and one or plural positions where pad touches or presses headwith each different pressure.
 15. The timpani of claim 14, which have;Two control sources, switches or pseudo switches for each timpano tokeep one of control positions, and foot pedal for specifying momentarycontrol positions, wherein control position giving bigger pressure isused at each timpano.
 16. The timpani of claim 7, further comprising:Soft pads with each actuator to push said soft pads to the heads orremove said soft pads from the heads, wherein said actuators take one ofcontrol positions, which are removed position, and one or pluralpositions where pad touches or presses head with each differentpressure. Wherein said tuning program memory also storing controlpositions of said actuators of soft pads for each timpano at eachprogram step.
 17. Computer readable media, which is prepared for timpaniof claim 10 and also prepared for each music work using timpani,including; Timpani set information consisting of possible differentpairs of data specifying combination of timpani regarding to diameterand linkage data to corresponding tuning program, Tuning programinformation to be loaded into said tuning program memory, prepared oneeach for different linkage data in timpani set information.
 18. Computerreadable media of claim 17 further including; Muffling specificationdata stored with tuning program information to be loaded into tuningprogram memory, prepared one each for different linkage data in timpaniset information.
 19. Computer readable media of claim 17 furtherincluding; Music note data for timpani part of the music work, preparedone each for different tuning program, printable and viewable from acomputer, and including marks for program step advance, which show thetiming for player to operate.